叶片式气液混输泵全流道内流场特性分析

Research on the flow characteristics for the whole flow passage of a multiphase rotodynamic pump is insufficient. Therefore, based on ANSYS_CFX, simulations are performed for the flow in such a pump with the medium of air-water. Structured grids for the computational domain are generated using ICEM_CFD and TurboGrid. The reliability of simulation is verified by comparing with the experimental data. The results show that, under different inlet gas void fraction (IGVF) conditions, the gas in the impeller mainly accumulated at the impeller hub and the closer to the impeller outlet and the blade suction surface, the higher degree for gas aggregation. With the increase of IGVF, the degree of gas aggregation in the impeller, as well as the gas inhomogeneity, is higher. The maximum value of the turbulence kinetic energy at IGVF=9%, 15% and 21% are respectively 1.07, 1.53 and 1.83 times than that at IGVF=3%. Meanwhile, the gas in the diffuser mainly accumulated near the hub and gradually spread toward the mainstream region along the flow direction. For IGVF=9%, the degree of gas aggregation in the impeller decreased gradually with the increase of flow rate, while in the diffuser, it is the largest at design condition (Q_d), followed by the large flow rate condition (1.25Q_d), then the small flow rate condition (0.75Q_d).The results above give a more in-depth understanding about the flow characteristics in such pumps, which will help in the optimization design and obtaining ahigher pump efficiency.